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Background: Jaundice in Plasmodium falciparum malaria is multifactorial and its incidence varies in different regions. It is important to assess the incidence and factors associated with malarial hepatopathy as well as its complications to understand the pattern of disease presentation in order to undertake appropriate interventional measures. There is a paucity of data with regard to malarial hepatopathy and its outcome at the global level. Aim: The study was conducted to assess the pattern, spectrum of biochemical parameters and complications of hepatopathy related to P. falciparum malaria. Materials and Methods: A descriptive study was conducted in a tertiary care hospital attached to a government medical institution in Assam, India. Demographic details of the hundred patients with P. falciparum malaria, their clinical and biochemical parameters, complications and outcome were collected using a prestructured proforma. Data was compared using proportion and Chi Square test. Results: The proportion of those with malarial hepatopathy was 38% and the incidence was more in males and younger age group. The degree of hyperbilirubinemia, complications that include renal failure, shock, acute respiratory distress syndrome, hypoglycemia and mortality were significantly more among patients with hepatopathy (P<0.05). Conclusion: Malarial hepatopathy is associated with a higher incidence of complications like renal failure, shock, acute respiratory distress syndrome and hypoglycemia. Further studies are required to elucidate the factors associated with malarial hepatopathy and to prevent the complications and mortality. [ABSTRACT FROM AUTHOR]

Abstract  We present a detailed study on fluorescence enhancement by ‘stroboscopic’ illumination with light pulses having duration ranging from few milliseconds to sub-picoseconds. We show how a delicate balance between pulse width and pulse repetition rate can result in an unprecedented fluorescence enhancement that has immediate applications in fluorescence imaging. [ABSTRACT FROM AUTHOR]

Abstract  We investigate the relative photo-damage effects during one- and two-photon excitations and demonstrate that there exist fundamental differences in the damage induced by a high repetition rate laser as compared to that of a CW laser. This difference is evident from the degree of enhanced fluorescence intensity achieved by blanking the excitation with an optical chopper. Such an enhancement in fluorescence intensity provides better signal-to-noise ratio that could have immediate applications in multiphoton imaging of live specimens. [ABSTRACT FROM AUTHOR]

In multiphoton fluorescence laser-scanning microscopy, ultrafast laser pulses i.e., light pulses having pulse width 1 ps(1 ps=10−12 s) are commonly employed to circumvent the low-multiphoton absorption cross-sections of common fluorophores. Because of the broad overlapping two-photon absorption spectra of fluorophores and the large spectral bandwidth of a short pulse, simultaneous excitation of many fluorophores is common, which justifies a persistent demand for selective excitation of individual fluorophores. We describe the use of pulse-pair excitation with possibilities of controlling molecular fluorescence in laser-scanning microscopy and compare it with coherent control using pulse sequence De and Goswami, “Coherent control in multiphoton fluorescence imaging,” Proc. SPIE 7183, 71832B (2009). [ABSTRACT FROM AUTHOR]

Selective excitation of a particular fluorophore in the presence of others demands clever design of the optical field interacting with the molecules. We describe the use of 20- to 50-GHz pulse-train excitation leading to two-photon absorption, followed by successive one-photon stimulated emission as a potential technique in the context of controlling two-photon molecular fluorescence, with applications in microscopy. [ABSTRACT FROM AUTHOR]

An effective z-scan setup with a minimum thermal effect is shown for intensity-dependent measure of two-photon absorption (TPA) with high-repetition rate lasers. Use of an additional intensity modulation with an optical chopper provides enough blanking time for a high-repetition rate laser to yield equally accurate results in TPA measurements compared to a low repetition laser. Extension of this method of thermal effect management with an optical chopper to emission studies also results in good correspondence for two-photon cross-section measurements from either z-scan or two-photon fluorescence techniques. The method also significantly enhances two-photon fluorescence, which could be promising for multiphoton microscopy. [ABSTRACT FROM AUTHOR]